Publication Abstracts
Grant et al. 2025, in press
Grant, I., W. Ni-Meister, and N.Y. Kiang, 2025: Multiscale analysis of global variation in allometric relationships: Implications for global vegetation models. Environ. Res. Ecol., in press, doi:10.1088/2752-664X/add7e3.
Allometric relationships governing trees' size and shape are a critical component of global models of vegetation and ecosystem dynamics. However, empirical variation in these relationships poses a challenge for models that rely on allometric parameters. We analyzed trees from the global Tallo database to assess empirical allometric variation at multiple scales, fitting allometric models to biome-continent and biome-plant functional type (PFT) aggregations as well as to individual sites. Our results provide new insight into global allometric variability compared to Metabolic Scaling Theory (MST) for relations between height (H), stem diameter (D), crown radius (CR), and crown volume (CV). We found that the degree of within-biome variation across continents depends on biome, with tropical rain forests exhibiting much less variation than temperate broadleaf forests. Moreover, the PFT (angiosperms vs. gymnosperms, leaf type, phenology) can explain allometric divergence in similar climates. The scaling exponents of most biome-PFT groups fall below the MST predictions for both H-D and CR-H allometry. Needleleaf trees have high H-D scaling exponents, while broadleaf trees have low H-D scaling exponents, and leaf type corresponds closely to disparate scaling exponents in very arid groups. At the site level, we found a clear positive relationship between within-site 95th percentile height and H-D scaling exponent. Since height can be inferred from remote sensing, we suggest that this relationship could support models of global variation in H-D allometry. We found the geographic scale of spatial correlation among H-D and CR-H scaling exponents to be significant for sites less than 250 km apart and to decline at greater distances. In order to demonstrate our results' relevance to biomass models, we estimated allometric parameters for a waveform-to-biomass model that uses Global Ecosystem Dynamics Investigation (GEDI) lidar measurements. Finally, we derive insights to support dynamic global vegetation models for carbon flux and stock estimates.
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BibTeX Citation
@unpublished{gr04210u,
author={Grant, I. and Ni-Meister, W. and Kiang, N. Y.},
title={Multiscale analysis of global variation in allometric relationships: Implications for global vegetation models},
year={2025},
journal={Environmental Research: Ecology},
doi={10.1088/2752-664X/add7e3},
note={Manuscript accepted for publication}
}
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RIS Citation
TY - INPR ID - gr04210u AU - Grant, I. AU - Ni-Meister, W. AU - Kiang, N. Y. PY - 2025 TI - Multiscale analysis of global variation in allometric relationships: Implications for global vegetation models JA - Environ. Res. Ecol. JO - Environmental Research: Ecology DO - 10.1088/2752-664X/add7e3 ER -
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